The following patents and applications are representative of various types of vacuum cleaners and filter systems:
United States Patent Application No. 2012/0279185 A1 to Appelo describes a vacuum cleaner primary filter cage wall element that is adapted to form, together with at least one complementary filter cage wall element, a tubular bag-house filter cage segment. The filter cage wall elements are provided with snap-locks, for snapping a first long side of the primary filter cage wall element to a secondary long-side of the complementary filter cage wall element, and for snapping a secondary long side of the primary filter cage wall element to a first long side of the complementary filter cage wall element.
U.S. Pat. No. 8,533,906 B2 to Liu describes vacuum cleaner comprising a receptacle having a working air inlet and an associated filter, the filter in communication with and downstream from the working air inlet, is disclosed. The vacuum cleaner further includes a housing containing a motor and having a cooling air outlet from the motor and a working air outlet, the working air outlet in communication with the working air inlet of the receptacle through a working air impeller, wherein the cooling air is directed to the receptacle, and the cooling air passes through the filter before exiting the working air outlet of the housing.
U.S. Pat. No. 8,206,482 B2 to Williams et al. describes vacuum cleaner filters, in particular replaceable vacuum cleaner filters suitable for both dry and wet/dry type vacuum cleaners, as well as systems incorporating the use of such filters and methods for their use. The filters include a plurality of adjacently positioned pleats arranged in a closed circumferential, cylindrically-shaped path, a top end cap having a central orifice capable of constricting a post on a vacuum filter cage, and optionally a molded end ring oppositely-spaced from the top end cap for engagement with the motor housing of a vacuum cleaner.
U.S. Pat. No. 6,428,610 B1 to Tsai et al. describes a filter media for a high efficiency particulate air (“HEPA”) filter including a multiplicity of adjacent electrostatically charged piles of nonwoven fabric. The invention further includes a method of making a HEPA filter.
U.S. Pat. No. 6,113,663 to Liu describes a vacuum cleaner having a dual filter assembly includes a filter cage, a primary filter disposed on the filter cage, and a secondary filter disposed downstream of the primary filter. A float valve between the primary filter and the secondary filter inhibits liquid from coming into contact with the secondary filter.
U.S. Pat. No. 6,110,248 to Liu at al. describes a dual filter assembly for a vacuum cleaner that includes an annular inner filter mountable on a filter cage of the vacuum cleaner. The inner filter has a lower end and a retaining ring is attached to the lower end. An annular outer filter is removably mounted surrounding the inner filter, with a lower end of the outer filter supported by the retaining ring.
U.S. Pat. No. 5,855,634 to Berfield describes a filter retainer for a vacuum cleaner that includes a filter cage having several ribs. At the bottom of the filter cage is a lip which includes a plurality of notches. A cylindrical filter having open ends is slid over the filter cage. A cap is placed at the bottom of the filter in order to hold the filter to the filter cage. The cap has a pair of ramps which engage notches on the rim of the filter cage. As the cap is rotated, the cap is pushed towards the filter so that a lip on the cap engages a bottom of the filter.
U.S. Pat. No. 5,783,086 to Scanlon et al. describes an improved method of employing a wet/dry vacuum cleaner for wet material pick-up. By employing a hydrophobic and air permeable filter material, such as an expanded polytetrafluoroethylene (PTFE), with a tight gasket around its edge in a place of a conventional wet/dry vacuum filter, it has been determined that the filter can be retained in place at all times during operation, regardless of the material being collected.
U.S. Pat. No. 5,308,485 to Griffin et al. describes a filter assembly for use in a bag-house having a cell plate provided with openings. The filter assembly includes a collar, filter bag, tubular supporting cage and locking ring. The filter bag filters particulate material and extends from below the cell plate. The collar supports the filter bag and has a longitudinally extended portion and a flange portion. The longitudinally extended portion is affixed to the filter bag below the cell plate, while the flange portion extends along the cell plate as a rim above a respective opening. The collar acts as a gasket to seal a respective opening in the cell plate. The tubular supporting cage has a longitudinally extended portion that structurally supports the filter bag. The locking ring is integrally fixed to the supporting cage and locks an arrangement of the filter bag, collar and cage in place. The locking ring also can include a venturi affixed thereto to assist in filtering and cleaning operations.
U.S. Pat. No. 5,308,369 to Morton et al. describes a cylindrical filter bag including a wire mesh cage with an access opening in the cage proximate to the open end of the filter bag. A resilient snap band is provided around the outer circumference of the cylindrical filter bag. The snap band includes a pair of felt rings formed around the band and an annular groove between the rings. The snap band thus provided can be depressed into the access opening in the wire mesh cage to allow the filter bag to be readily positioned in an airtight manner within a circular hole provided in the tube sheet of a dust collector. The hole in the tube sheet is provided with a collar having a radially extended flange portion that is attached to the top surface of the tube sheet to center the collar above the hole. The wire tube mesh cage of the filter bag is further provided with a reinforcing sleeve that mates with the tube sheet collar, and a venturi that is positioned concentrically within the sleeve.
U.S. Pat. No. 5,069,696 to Bruno describes a shop type vacuum cleaner including an externally mounted filter including a filter housing including a filter element and an elongated inlet tube slidably received within an exhaust outlet opening from the vacuum cleaner debris compartment.
U.S. Pat. No. 4,906,265 to Berfield describes installing a dry material paper filter on the filter cage of an electric vacuum cleaner, a disk of porous paper filtering material or of cloth type fabric, laid over the panel enclosing the bottom of the filter cage and a ring is pressed up over the paper or cloth filter and over the panel. As the ring is drawn up over the filter cage, it folds and presses the paper or cloth filter around the filter cage. At the top of the filter cage, the ring secures the filter to the cage. An additional filtering sleeve may be disposed around the filter cage before the filter is installed over the cage and over the sleeve with the attachment ring. The sleeve may be of foam or other wet material filtering material. The filter installed with the ring is of dry filtering material, like paper or cloth. A marking or disk at the center of the filter helps a user place the filter over the filter cage before the ring is used to fold the filter into place.
U.S. Pat. No. 3,830,042 to MacDonnell describes a disposable filter bag for the intake air housing of a locomotive that has a generally rectangular box-shaped extended configuration and is of pliable sheet stock of full flow depth filter material to be collapsible for folding into compact form. The bag is mounted between external and internal cage-like frames that stabilize the extended configuration of the bag.
U.S. Pat. No. 3,478,498 to Sauermann describes a filter that comprises a frame and a filter element carried by the frame to define therewith an internal chamber. The filter element consists of two apertured supporting layers and a filter layer of fibrous filter material sandwiched therebetween. A plurality of supporting bars is located in the internal chamber and engages the inner surfaces of the filter element. A plurality of deflecting bars engage the outer surfaces of the filter element intermediate the reinforcing bars and deflect the filter element intermediate such reinforcing bars inwardly into the chamber.
U.S. Pat. No. 9,161,667 to Sobel describes a filter kit with an enhanced surface area filter and cage, for an electric power vacuum cleaner. The filter is a self-cleaning, flexible interlocking fabric having a rest position at atmospheric pressure, and a stretched position when under vacuum of a vacuum cleaner, the fabric having at least enough stretchability to increase its surface area by at least 10% in its stretched position from its rest position. When the vacuum cleaner is operating, the filter is in its stretched position and collects dust and debris, and when the vacuum cleaner is off, the filter relaxes, returns to its rest position and its surface area contracts to be self-cleaning, and a portion of the dust and debris to fall from the filter.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.